U.S. patent application number 10/505640 was filed with the patent office on 2005-03-31 for treating liquid for surface treatment of aluminum or magnesium based metal and method of surface treatment.
Invention is credited to Ishikura, Kazuhiro, Kurosawa, Michiro, Matsushita, Tadashi, Nakayama, Takaomi, Okada, Eisaku, Sato, Hiroyuki, Shiota, Katsuhiro, Yoshida, Fumiya.
Application Number | 20050067057 10/505640 |
Document ID | / |
Family ID | 27790969 |
Filed Date | 2005-03-31 |
United States Patent
Application |
20050067057 |
Kind Code |
A1 |
Ishikura, Kazuhiro ; et
al. |
March 31, 2005 |
Treating liquid for surface treatment of aluminum or magnesium
based metal and method of surface treatment
Abstract
A composition for surface treatment of aluminium, aluminum
alloy, magnesium or magnesium alloy and the treating solutions
being diluted to the desired concentration are defined. A said
composition of this invention containing (1) compound A containing
at least one metal element selected from the group consisting of
Hf(IV), Ti(IV) and Zr(IV), (2) fluorine containing compound of
sufficient amount to make fluorine existed in the composition at
least by 5 times of molarity to the total molarity of metal
contained in above mentioned compound A, (3) at least one metal ion
B selected from the group of alkaline earth metals, (4) at least
one metal ion C selected from the group consisting of Al, Zn, Mg,
Mn and Cu, and (5) nitric ion and the mol concentration of compound
A is 0.1-50 mmol/L as metal element of Hf(IV), Ti(IV) and Zr(IV).
The metal treated with the treating method applying the present
invention solution has excellent resistance to various corrosive
environments.
Inventors: |
Ishikura, Kazuhiro; (Tokyo,
JP) ; Kurosawa, Michiro; (Tokyo, JP) ;
Nakayama, Takaomi; (Totyo, JP) ; Sato, Hiroyuki;
(Totyo, JP) ; Matsushita, Tadashi; (Totyo, JP)
; Okada, Eisaku; (Toyota-shi, JP) ; Yoshida,
Fumiya; (Ikeda-shi, JP) ; Shiota, Katsuhiro;
(Ikeda-shi, JP) |
Correspondence
Address: |
FLYNN THIEL BOUTELL & TANIS, P.C.
2026 RAMBLING ROAD
KALAMAZOO
MI
49008-1699
US
|
Family ID: |
27790969 |
Appl. No.: |
10/505640 |
Filed: |
August 19, 2004 |
PCT Filed: |
June 12, 2002 |
PCT NO: |
PCT/JP02/05861 |
Current U.S.
Class: |
148/273 ;
148/275 |
Current CPC
Class: |
C23C 22/44 20130101;
C23C 22/34 20130101 |
Class at
Publication: |
148/273 ;
148/275 |
International
Class: |
C23C 022/34 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 5, 2002 |
JP |
2002-059041 |
Mar 5, 2002 |
JP |
2002-059042 |
Claims
1. A composition for surface treatment of aluminum, aluminum alloy,
magnesium or magnesium alloy comprising components (1) to (5); (1)
compound a containing at least one metal element selected from the
group consisting of Hf(iv), Ti(iv) and Zr(iv), (2) fluorine
containing compound of sufficient amount to make fluorine existed
in the composition at least by 5 times of molarity to the total
molarity of metal contained in above mentioned compound a, (3) at
least one metal ion b selected from the group of alkaline earth
metals, (4) at least one metal ion c selected from the group
consisting of Al, Zn, Mg, Mn and Cu, and (5) nitric ion.
2. A treating solution for surface treatment of aluminum, aluminum
alloy, magnesium or magnesium alloy comprising components (1) to
(5); (1) 0.1 to 50 mmol/L of compound A containing at least one
metal element selected from the group consisting of Hf(IV), Ti(IV)
and Zr(IV) as said metal element, (2) fluorine containing compound
of sufficient amount to make fluorine existed in the composition at
least by 5 times of molarity to the total molarity of metal
contained in above mentioned compound A, (3) at least one metal ion
B selected from the group of alkaline earth metals, (4) at least
one metal ion C selected from the group consisting of Al, Zn, Mg,
Mn and Cu, and (5) nitric ion.
3. The treating solution for surface treatment of aluminum,
aluminum alloy, magnesium or magnesium alloy of claim 2, wherein
total concentration of metal ion B is from 1 to 500 ppm.
4. The treating solution for surface treatment of aluminum,
aluminum alloy, magnesium or magnesium alloy of claim 2, wherein
total concentration of metal ion C is from 1 to 5000 ppm.
5. The treating solution for surface treatment of aluminum,
aluminum alloy, magnesium or magnesium alloy according to claim 2,
wherein the concentration of nitric ion is from 1000 to 30000
ppm.
6. The treating solution for surface treatment of aluminum,
aluminum alloy, magnesium or magnesium alloy according to claim 2,
to which at least one compound selected from the group consisting
of HClO.sub.3, HBrO.sub.3, HNO.sub.2, HmnO.sub.4, HVO.sub.3,
H.sub.2O.sub.2, H.sub.2WO.sub.4, H.sub.2MoO.sub.4 and oxygen acid
salt thereof are further added.
7. The treating solution for surface treatment according to claim
2, wherein the pH of the solution is 3 to 6.
8. A method for surface treatment of aluminum, aluminum alloy,
magnesium or magnesium alloy comprising, contacting said metals
with the treating solution for surface treatment according to claim
2.
9. A method for treatment before coating of metal materials
containing at least one metal selected from the group consisting of
aluminum, aluminum alloy, magnesium or magnesium alloy as the
component comprising, contacting said metals with the treating
solution for surface treatment according to claim 2.
10. A surface treated metal material comprising, possessing a
surface treated mm layer obtained by the method for surface
treatment of claim 8 on the surface of aluminum, aluminum alloy,
magnesium or magnesium alloy, wherein the deposite weight per unit
area of said surface treated film layer is larger than 10
mg/m.sup.2 as the metal element contained in compound A.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a composition for surface
treatment used for the purpose to deposit a surface treated film
giving good resistance against the corrosion environment to metals
such as aluminum or aluminum alloy, magnesium or magnesium alloy in
which these metals are used without coating or better resistance to
corrosion environment not discharging waste e.g. hexavalent chrome,
a treating solution for surface treatment and a method for surface
treatment. The present invention further relates to a treated metal
material which has excellent corrosion resistance to various
environment.
DESCRIPTION OF THE PRIOR ART
[0002] Aluminum and aluminum alloy are applied increasingly in the
field of car parts industry to lighten a car. For example, for
cylinder head cover, cylinder head, crank case and timing gear
case, which are the parts connecting with engine, aluminum alloy
die cast e.g. ADC10 or ADC12 are used and 5000 alloy or 6000 alloy
are used. Currently the magnesium and magnesium alloy are also used
from the same view point.
[0003] Furthermore, aluminum, aluminum alloy, magnesium and
magnesium alloy are applied in other fields than car body. And the
conditions of use for these metals and metal alloys are variable,
namely, sometimes used with coating after molded and sometimes used
without coating. Therefore, the functions necessary for surface
treatment are variable, and the functions which meet to the
exposing atmosphere, for example, adhesion or corrosion resistance
of uncoated metal and corrosion resistance after coated are
required.
[0004] As the surface treatment to be performed on aluminum,
aluminum alloy, magnesium and magnesium alloy, a chromate treatment
using hexavalent chrome is popular. The chromate treatments can be
classified to two types, one contains hexavalent chrome in film and
the other one does not contain hexavalent chrome in film, however
both treatment contain hexavalent chrome in the waste solution.
Therefore, this chromate method is not so desired from the view
point of environmental regulation.
[0005] As the surface treating method not using hexavalent chrome
is, a zinc phosphate treatment. For the purpose to deposit a zinc
phosphate film on the surface of aluminum, aluminum alloy,
magnesium and magnesium alloy, various inventions were proposed.
For example, in JP6-99815 publication, the method to deposit zinc
phosphate film, which has excellent corrosion resistance,
especially scab corrosion resistance after cathodic
electrodeposition coating is proposed. This method is characterized
by regulating the concentration of fluorine in zinc phosphate film
treating solution, further by regulating molar ratio of complex
fluoride to fluorine and the concentration of activated fluorine
measured by a silicon electrode meter into a specific
limitation.
[0006] Further, in JP3-240972A Laid Open Publication, the method to
form a zinc phosphate film, which is excelling in the corrosion
resistance and especially in scabbing resistance after cathodic
electrodeposition coating is proposed. This method is characterized
by regulating the concentration of fluorine, keeping lower limit of
molar ratio of complex fluoride to fluorine and using zinc
phosphate treating solution in which activated fluorine
concentration measured by a silicon electrode meter is kept into a
specific limitation. Adding to this operation, aluminum ion is
precipitated from said zinc phosphate treating solution by adding
fluorine after said zinc phosphate treating solution is introduces
in the outside of a zinc phosphate treating bath.
[0007] These methods are aiming to improve the zinc phosphate
treatment ability to aluminum alloy by increasing the fluorine ion
concentration in zinc phosphate treating solution. However, it is
difficult to obtain good corrosion resistance of uncoated metal by
zinc phosphate film, further, since aluminum ion solved out at the
zinc phosphate treatment causes the increase of the waste product
by forming sludge.
[0008] In JP6-330341A Laid Open publication, discloses the zinc
phosphate treating method for magnesium alloy. Said method is
characterizing by containing specific concentration of zinc ion,
manganese ion, phosphate ion, fluoride and an accelerator for film
depositing and by keeping upper limits of concentration of nickel
ion, cobalt ion and copper ion. Further, in JP8-134662A Laid Open
publication, the method to remove the settle out magnesium ion by
adding fluorine to the zinc phosphate treating solution for
magnesium.
[0009] Above mentioned methods are both aiming the substrate
treatment for coating, therefore it is difficult to obtain
sufficient corrosion resistance of uncoated metals by a zinc
phosphate film. Furthermore, as shown in JP8-134662A Laid Open
publication, the generation of sludge, can not be avoided as long
as a zinc phosphate treatment is used. The method to form a surface
treated film having good adhesion and the corrosion resistance
after coating without containing hexavalent chrome in the treating
solution except the zinc phosphate treatment, the surface treating
solution for aluminum or aluminum alloy containing through vanadium
compound is disclosed in JP56-136978A Laid Open publication. This
method is desired to obtain the surface treated film which is
relatively excess in corrosion resistance of uncoated metal,
however, the metal to be treated is only an aluminum alloy alone,
and further it is necessary high temperature condition of
80.degree. C. to obtain a surface treated film.
[0010] In JP5-222321A Laid Open publication, aqueous composition of
treatment before coating for aluminum or aluminum alloy containing
water soluble poly(meta)acrylic acid or salts thereof and at least
one or more than two of water soluble compound of metal selected
from the group consisting of Al, Sn, Co, La, Ce and Ta is
disclosed. And in JP9-25436A Laid Open publication, the surface
treating composition for aluminum alloy containing organic polymer
compound which contains at least one nitrogen atom or salt thereof,
heavy metal or salt thereof, which is water soluble, water
dispersible or emulsifyable is disclosed. These compositions are
limitingly used to the surface treatment of aluminum alloy, and the
performance of corrosion resistance of uncoated metal is not
desirable.
[0011] Further JP2000-199077 Laid Open publication shows a surface
treating composition, a treating solution for surface treatment and
a surface treating method for metal surface of aluminum, magnesium
or zinc composed of at least one compound selected from the group
consisting of metal acetylacetonate, water soluble inorganic
titanium compound and water soluble inorganic zirconium compound.
According to this method, it is possible to form a surface treated
film having good corrosion resistance of uncoated metals. However,
in said solution for surface treating of mentioned invention
organic compound is used, and this organic compound can be an
obstacle for establishing the closed system of water rinsing
process after the film depositing treatment process.
[0012] As mentioned above, the conventional art, do not make
possible to form a surface treated film which has excellent
corrosion resistance of uncoated and the corrosion resistance after
coated on the surface of aluminum, aluminum alloy, magnesium or
magnesium alloy, using treating solution which does not discharge
waste such as sludge and does not contain harmful component to the
environment.
DISCLOSURE OF THE INVENTION
[0013] The object of the present invention is to provide a
composition for surface treatment, a treating solution for surface
treatment and a surface treating method which are aiming to form a
surface treated film excels in corrosion resistance of uncoated
metal and the corrosion resistance after coated on the surface of
aluminum, aluminum alloy, magnesium or magnesium alloy using a
treating solution which does not discharge waste such as sludge and
does not contain harmful component to the environment such as
hexavalent chrome. Further another object of the present invention
is to provide said metal material which are excelling in corrosion
resistance of uncoated metal and the corrosion resistance after
coated.
[0014] The present invention is the composition for surface
treatment of aluminum, aluminum alloy, magnesium or magnesium alloy
comprising components (1)-(5);
[0015] (1) compound A containing at least one metal element
selected from the group consisting of Hf(IV), Ti(IV) and
Zr(IV),
[0016] (2) fluorine containing compound of sufficient amount to
make fluorine existed in the composition at least by 5 times of
molarity to the total molarity of metal contained in above
mentioned compound A,
[0017] (3) at least one metal ion B selected from the group of
alkaline earth metal,
[0018] (4) at least one metal ion C selected from the group
consisting of Al, Zn, Mg, Mn and Cu, and
[0019] (5) nitric ion.
[0020] Further, the present invention is the treating solution for
surface treatment of aluminum, aluminum alloy, magnesium or
magnesium alloy comprising components (i)-(5);
[0021] (1) 0.1 to 50 mmol/L of compound A containing at least one
metal element selected from the group consisting of Hf(IV), Ti(IV)
and Zr(IV) as said metal element,
[0022] (2) fluorine containing compound of sufficient amount to
exist fluorine in the treating solution at least by 5 times
molarity to the total molarity of metal contained in above
mentioned compound A,
[0023] (3) at least one metal ion B selected from the group of
alkaline earth metal,
[0024] (4) at least one metal ion C selected from the group
consisting of Al, Zn, Mg, Mn and Cu, and
[0025] (5) nitric ion.
[0026] In above mentioned treating solution for metal surface
treatment, the desirable total concentration of alkaline earth
metal ion B is from 1 to 500 ppm, and desirable concentration of
metal ion C is from 1 to 5000 ppm. Further, the desirable
concentration of nitric ion is from 1000 to 30000 ppm. To the above
mentioned treating solution for metal surface treatment, can
further add at least one compound selected from the group
consisting of HClO.sub.3, HBrO.sub.3, HNO.sub.2, HMnO.sub.4, HVO3,
H.sub.2O.sub.2, H.sub.2WO.sub.4, H.sub.2MoO.sub.4 and oxygen acid
salt thereof. And the desirable pH of the treating solution for
metal surface treatment is from 3 to 6.
[0027] Moreover, the present invention provides the method for
metal surface treatment by contacting aluminum, aluminum alloy,
magnesium or magnesium alloy with above mentioned treating solution
for metal surface treatment. Further, the present invention
provides the method for metal surface treatment by contacting metal
material containing at least one metal selected from the group
consisting of aluminum, aluminum alloy, magnesium or magnesium
alloy as a component with above mentioned treating solution for
metal surface treatment. Furthermore, the present invention
provides the surface treated metal material comprising, possessing
a surface treated film layer obtained by above mentioned method for
metal surface treatment on the surface of aluminum, aluminum alloy,
magnesium or magnesium alloy, wherein the coating amount of said
surface treated film layer is larger than 10 mg/m.sup.2 as the
metal element contained in above mentioned compound A
DESCRIPTION OF THE PREFERRED EMBODYMENT
[0028] The present invention relates to the surface treatment of
aluminum, aluminum alloy, magnesium or magnesium alloy, and this
surface treatment can be applied to the metal material combining at
least two kind of aluminum, aluminum alloy, magnesium or magnesium
alloy, further can be applied to the metal material combining at
least one metal selected from the group consisting of aluminum,
aluminum alloy, magnesium or magnesium alloy with a steel or a zinc
plated steel. And this surface treatment is useful for the previous
treatment for coating of a car body composed by these metal
materials.
[0029] The composition for metal surface treatment of the present
invention is the composition containing (1) compound A containing
at least one metal element selected from the group consisting of
Hf(IV), Ti(IV) and Zr(IV), (2) fluorine containing compound of
sufficient amount to exist fluorine in the composition at least by
5 times molarity to the total molarity of metal contained in above
mentioned compound A, (3) at least one metal ion B selected from
the group of alkaline earth metal, (4) at least one metal ion C
selected from the group consisting of Al, Zn, Mg, Mn and Cu and (5)
nitric ion.
[0030] As the compound A containing at least one metal element
selected from the group consisting of Hf(IV), Ti(IV) and
Zr(IV)(hereinafter shortened to compound A), for example,
HfCl.sub.4, Hf(SO.sub.4).sub.2, H.sub.2HfF.sub.6, salt of
H.sub.2HfF.sub.6, HfO.sub.2, HfF.sub.4, TiCl.sub.4,
Ti(SO.sub.4).sub.2, Ti(NO.sub.3).sub.4, H.sub.2TiF.sub.6, salt of
H.sub.2TiF.sub.6, TiO.sub.2, TiF.sub.4, ZrCl.sub.4,
Zr(SO.sub.4).sub.2, Zr(NO.sub.3).sub.4, H.sub.2ZrF.sub.6, salt of
H.sub.2ZrF.sub.6, ZrO.sub.2 and ZrF.sub.4 are available. These
compounds can be used together with.
[0031] As the fluorine containing compound of the component (2) of
the present invention, hydrofluoric acid, H.sub.2HfF.sub.6,
HfF.sub.4, H.sub.2TiF.sub.6, TiF.sub.4, H.sub.2ZrF.sub.6,
ZrF.sub.4, HBF.sub.4, NaHF.sub.2, KHF.sub.2, NH.sub.4HF.sub.2, NaF,
KF and NH.sub.4F are available. These fluorine containing compounds
can be used together with.
[0032] As at least one metal ion B selected from the group of
alkaline earth metal of the component (3) (hereinafter shortened to
alkaline earth metal B) is the element belonging to 2.sup.nd group
of periodic law list except Be and Ra, desirably Ca, Sr or Ba. In
general, although elements belonging to 2.sup.nd group of periodic
law list are called as alkaline earth metals, the property of Be is
different from that of other alkaline earth metal and since Be and
Be compound have strong toxicity, these are out of the object of
the present invention that does not contain harmful component to
the environment. While, Ra is a radioactive element, and concerning
it's troublesome handling, the industrial use of Ra is not so
practical. Therefore, in the present invention, elements belonging
to 2.sup.nd group of periodic law list except Be and Ra are used.
As the supply source of alkaline earth metal ion B, oxide,
hydroxide, chloride, sulfate, nitrate and carbonate of said metals
can be mentioned are available.
[0033] Metal ion C of the component (4) used in the present
invention, is at least one metal ion selected from the group
consisting of Al, Zn, Mg, Mn and Cu (hereinafter shortened simply
to metal ion C). As the supplying source of metal ion C, for
example, oxide, hydroxide, chloride, sulfate, nitrate and carbonate
of said metals can be mentioned. Further, as the supplying source
of nitric ion of the component (5) of the present invention, nitric
acid or nitrate can be used.
[0034] Practically, the composition for metal surface treatment
mentioned above is diluted by water to the treating solution for
metal surface treatment. This treating solution for metal surface
treatment of the present invention contains at least one metal
element selected from the group consisting of Hf(IV), Ti(IV) and
Zr(IV) by total molar concentration of 0.1-50 mmol/L, desirably
0.2-20 mmol/L. Said metal element which is supplied from compound A
in the present invention, is the main component of a surface
treated film. Therefore, when the total molar concentration of said
metal element is smaller than 0.1 mmol/L, the concentration of the
main component of surface treated film becomes small and the enough
thickness of film to perform sufficient corrosion resistance of
uncoated metal and the corrosion resistance after coated can not be
obtained by short treatment time. And when the total molar
concentration of said metal element is larger than 50 mmol/L,
although the surface treated film can be deposited sufficiently,
the ability of the corrosion resistance can not be increased and is
disadvantageous as is expected and it is not advantageous from the
economical view point.
[0035] The concentration of fluorine in fluorine containing
treating solution for surface treatment of metal is at least by 5
times molarity to the total molarity of metal contained in above
mentioned compound A. Desirably at least 6 times to the total
molarity of above mentioned metals. The fluorine concentration is
adjusted by regulating the amount of fluorine containing compound
of the component (2).
[0036] The fluorine component of fluorine containing compound of
the present invention has following two functions. The first one is
to maintain metal elements contained in compound A of the treating
solution stable in the condition of treating bath. And the second
one is to etch the surface of aluminum, aluminum alloy, magnesium
or magnesium alloy and to maintain aluminum ion or magnesium ion
solved out into the treating solution for surface treatment stable
in the treating bath.
[0037] To initiate the etching reaction of aluminum, aluminum
alloy, magnesium or magnesium alloy by fluorine, it is necessary
that the fluorine concentration is at least 5 times to the total
molarity of metal elements contained in compound A. If the fluorine
concentration is smaller than 5 times to the total molarity of
metal elements contained in compound A, the fluorine in the
treating solution of surface treatment is only used to maintain the
stability of metal elements contained in compound A, and the
sufficient etching amount can not be obtained, further, since the
pH to form the oxide of above mentioned metal elements on the metal
surface to be treated can not be achieved, the coating amount
sufficient to perform the corrosion resistance can not be
obtained.
[0038] In the case of zinc phosphate treatment, which is the
conventional art, sludge is generated from the process, because,
for example, aluminum ion solved out from aluminum alloy forms an
insoluble salt to phosphoric acid and fluorine and sodium ion forms
an insoluble salt called cliorite. On the contrary, when the
treating solution for surface treatment of the present invention is
used, sludge is not generated due to the solubilizing effect of
fluorine. Further, when the treating amount of the metal material
to be treated is remarkably large to the capacity of the treating
bath, for the purpose to solubilize the solved out metal material
component to be treated, an inorganic acid such as sulfuric acid,
hydrochloric acid or an organic acid such as acetic acid, oxalic
acid, tartaric acid, citric acid, succinic acid, gluconic acid or
phthalic acid or a chelating agent which chelate metal material
component to be treated can be added. These compounds can be used
together with.
[0039] The metal elements provided by the compound A can exist
stable in acidic aqueous solution, however, in alkaline aqueous
solution said metal elements form an oxide of each metal element.
Along with the etching reaction by fluorine of metal material to be
treated, the pH is elevated at the surface of metal material to be
treated and above mentioned metal elements forms an oxide on the
metal surface to be treated. Namely, an oxide film of these metal
elements is formed, and performance of the corrosion resistance is
enhanced.
[0040] The component (1) and the component (2) in a composition for
metal surface treatment or a treating solution for metal surface
treatment display above mentioned function and form an oxide film
of metal elements supplied from compound A on the surface of metal
material. To these components, at least one kind of metal ion B
selected from the group consisting of alkaline earth metal of the
component (3), at least one kind of metal ion C selected from the
group consisting of Al, Zn, Mg, Mn and Cu of the component (4) and
nitric ion of component (C) are further blended.
[0041] Generally, alkaline earth metals reacts with fluorine to
form fluorides. Alkaline earth metal ion B in the treating solution
for surface treatment of this invention generates fluoride and
consumes fluorine in the treating solution for surface treatment.
Along with the consumption of fluorine mentioned above, the
stability of the metal element supplied from the compound A
decrease. Therefore the pH value which allows to form an oxide
consisting main component of film becomes lower, and it makes
possible to lower the surface treatment temperature and shorter
treatment time. The desirable concentration of metal ion in the
solution for the metal surface treatment is 1-500 ppm and more
desirable concentration is 3-100 ppm. When the concentration is
lower than 1 ppm, above mentioned effect to accelerate the reaction
for depositing film can not be obtained. On the contrary, when the
concentration is larger than 500 ppm, the film of sufficient amount
to obtain good resistance to corrosion can be obtained, however,
the stability of the treating bath is spoiled. Therefore, the
problem which obstruct the continuous operation is caused.
[0042] Ordinary, the fluoride of alkaline earth metal is a compound
which is hard to be dissolved. One of the objects of this invention
is not to generate sludge. By further blending metal ion C of the
component (4) and nitric ion of the component (5) to the treating
solution for metal surface treatment of the present invention,
above mentioned fluoride of alkaline earth metal ion B can be
solubilized and the generation of sludge can be controlled.
Consequently, the reaction for film formation is accelerated and
the corrosion resistance of uncoated surface can be improved.
[0043] Metal ion C is an element which generate complex fluoride.
Therefore, metal ion C has the effect to consume fluorine in
treating bath and to accelerate the reaction to form the treated
film as well as alkaline earth metal ion B generates fluoride and
consumes fluorine. Further, metal ion C has a function to
solubilize alkarine earth metal ion B. Metal ion C makes fluoride
of alkaline earth metal ion B solubilize by generating complex
fluoride with fluorine. Furthermore, the solubility of alkaline
earth metal ion B is increased by adding nitric ion. That is, by
the present invention, it becomes possible to accelerate the
reaction for film formation maintaining the stability of the
surface treating solution by adding alkaline earth metal ion B,
metal ion C and nitric ion.
[0044] The solibilizing reaction of alkaline earth metal ion B by
metal ion C is illustrated as follows using example of Ca and Al as
follows.
CaF.sub.2+2Al.sup.3+=Ca.sup.2++2AlF.sup.2+
[0045] Still further, metal ion C has a function to improve
corrosion resistance of uncoated metal. At the present time, the
mechanism of improvement of corrosion resistance of metal ion C is
not dear. However, the inventors has conduced intensive study about
the relationship between metal to be added to the treated film
formed by using compound A and corrosion resistance of uncoated
metal, and has found out that the corrosion resistance of uncoated
metal can be remarkably improved by adding a specific metal ion,
namely metal ion C. The desirable concentration of metal ion C in
the treating solution for metal surface treatment is 1-5000 ppm,
and more desirable concentration is 1-3000 ppm. When the
concentration is smaller than 1 ppm, the above mentioned effect to
accelerate the reaction for film formation can not be obtained and
the function to solubilize the fluoride of alkaline earth metal can
not be obtained. And when the concentration is larger than 5000
ppm, although the formed film having sufficient amount to obtain
good resistance to corrosion can be obtained, the further improving
of the corrosion resistance can not be expected and is only
disadvantageous economically.
[0046] Even if the concentration of nitric ion is smaller than 1000
ppm, it is possible to form the treatment film of uncoated metals
has good resistance to corrosion. However, as the large amount of
alkaline earth metal ion B makes the treatment solution in a bath
unstable, nitric ion concentration is larger than this value. As
above mentioned result, it is concluded that the desired
concentration of nitric ion becomes 1000 ppm-30000 ppm. Now, the
reactivity of the treating solution to metal surface can be easily
survived by measuring the concentration of free fluorine ion.
[0047] Inventors conducted the measuring of concentration of
fluorine ion in the treating solution to determine the desirable
concentration of free fluorine ion is smaller than 500 ppm and more
desirably is smaller than 300 ppm. When the concentration of free
fluorine ion is larger than 500 ppm, it becomes hard to form a film
having enough amount to obtain good corrosion resistance of
uncoated or coated metals. These materials act as an oxidant and
accelerate the above mentioned film formation reaction. In the case
that these materials are used as an oxidant, the sufficient effect
is obtained by adding amount of 50-5000 ppm. On the contrary, more
higher concentration of these materials are needed as an etching
reagent.
[0048] To the treating solution for metal surface treatment of the
present invention, at least one compound selected from the group
consisting of HClO.sub.3, HBrO.sub.3, HNO.sub.2, HMNO.sub.4,
HVO.sub.3, H.sub.2O.sub.2, H.sub.2WO.sub.4, H.sub.2MoO.sub.4 and
salt of these oxygen acids can be added. At least one compound
selected from the group consisting of above mentioned oxygen acid
and salts thereof acts as an oxidant and accelerate the film
forming reaction of the present invention. There is no limitation
to the concentration of the above mentioned oxygen acids and salts
thereof to be added, however, in the case when these are used as an
oxidant, the sufficient effect is performed by the adding amount of
10-5000 ppm. Further, in the case when the above mentioned oxygen
acids and salts thereof also act as the acid to maintain the etched
metal material component in the treating bath, the adding amount
can be increased if necessary.
[0049] The pH of the solution for metal surface treatment of the
present invention is desirably to be 3-6. When the pH is lower than
3, the stability of the metal element supplied from compound A
becomes stable in the solution for surface treating, and it becomes
impossible to form enough amount of film to perform good corrosion
resistance and resistance in the short treatment time. Further, in
the case when pH is higher than 6, it is possible to form enough
amount of film sufficient to obtain good resistance to corrosion,
however, the film which has good corrosion resistance does not
easily obtained because the treating solution becomes unstable
under this pH condition.
[0050] In the present invention, the surface treated film layer can
be formed on the surface of aluminum, aluminum alloy, magnesium or
magnesium alloy by contacting these aluminum, aluminum alloy,
magnesium or magnesium alloy with above mentioned treating solution
for metal surface treatment. The desired methods are spraying
method, roll coating method or dipping method. At the contact, it
is desirable to set up the temperature of the treating solution for
surface treatment to 30-70.degree. C. If the treating temperature
is lower than 30.degree. C., the film formation needs longer time
than conventional treatment, such as zinc phosphate treatment or
chromate treatment. As zinc phosphate treatment time is two minutes
or chromate treatment time is about one minute, longer treatment
time than that of these treatment is not practical. On the
contrary, when the temperature is higher than 70.degree. C., it is
not economically advantageous because the remarkable time
decreasing effect is not obtained.
[0051] Generally, it is difficult to form the uniform films on the
objects composed from various kind of metals, for example car body
which is composed from steel, zinc plated, aluminum alloy or
magnesium alloy, because the less noble metal dissolves preferably
than noble metal. And, it is very difficult to form uniform film on
the surface of both two metal surfaces. The present invention
proposes the countermeasure to this problem. By the method of the
present invention, which dip the subject into the treating solution
for metal surface treatment, alkaline earth metal ion B reacts with
fluorine and generate fluoride and by said consumption of fluorine
in the composition the stability of metal element of compound A in
the treating bath is spoiled, therefore the pH value which make
form these oxide drops. As mentioned above, since the present
invention is to accelerate the film depositing reaction by adding
alkaline earth metal ion B, it becomes possible to form sufficient
amount of film enough to obtain the corrosion resistance on the
surface metal material such as a car body characterized that the
different metals are connected.
[0052] The depositing amount of surface treated film layer to the
metal material to be treated of the present invention is necessary
to be larger than 10mg/m.sup.2 as the total amount of at least one
metal element selected from the group consisting of Hf(IV), Ti(IV)
and Zr(IV). In the case that depositing amount is smaller than 10
mg/m.sup.2, weather the treated metal with coating has good
corrosion resistance or not depends on the surface condition or
components of alloys and 10 mg/m.sup.2 is the treshhold value to
keep excellent film.
EXAMPLE
[0053] Performance of the composition for surface treatment, the
treating solution for surface treatment and the method for surface
treatment of the present invention will be explained in accordance
to the Examples and Comparative Examples. The treated materials, a
degreasing agent and a coated material other than the treating
solutions of this invention are selected among the commercial
materials, and in the practical treating process before coating, it
is not restricted within these materials.
[0054] Test Plate
[0055] The abbreviation marks and details of the test plates used
in Examples and Comparative Examples are shown as follows.
[0056] ADC: (aluminum diecast:ADC12)
[0057] Al: (aluminum alloy plate: 6000 type aluminum alloy)
[0058] Mg: (magnesium alloy plate: JIS-H-4201)
[0059] Treating process
[0060] Examples and Comparative Examples except zinc phosphate
treatment are treated by following procedure.
[0061] alkali degreasing.fwdarw.rinsing by water.fwdarw.film
forming treatment.fwdarw.rinsing by water.fwdarw.rinsing by pure
water.fwdarw.drying
[0062] Zinc phosphate treatment in Comparative Example is treated
by following procedure.
[0063] alkali degreasing.fwdarw.rinsing by water.fwdarw.surface
conditioning.fwdarw.zinc phosphate treatment.fwdarw.rinsing by
water.fwdarw.rinsing by pure water.fwdarw.drying
[0064] In Examples and Comparative Examples, the alkali degreasing
is carried out as follows. That is, FINE CLEANER 315 (T.M.: Product
of NIHON PAKERIZING CO., LTD.) is diluted to 2% concentration by
tap water, and this diluted solution is sprayed to a plate at
50.degree. C. for 120 sec.
[0065] The rinsing process by water and the rinsing process by pure
water after film treatment process in Examples and Comparative
Examples are as follows; spraying water or pure water to a plate at
the room temperature for 30 sec.
Example 1
[0066] The composition for surface treatment is prepared with
aqueous solution of titanium sulfate (IV) and hydrofluoric acid.
The molarity ratio of Ti to HF in the composition is 7.0 and Ti
concentration is 100 mmol/L. Then Ca(NO.sub.3).sub.2 reagent and
ZnSO.sub.4 reagent and HNO.sub.3 are added, and the composition for
surface treatment is prepared. The prepared composition is diluted
by water and the obtained treating solution for surface treatment
has Ti concentration of 50 mmol/L, Ca concentration of 2 ppm, Zn
concentration of 1000 ppm and HNO.sub.3 concentration of 1000 ppm.
After degreased, a test plate is rinsed by water and kept into said
treating solution adjusted to pH 4.0 using ammonium aqueous
solution, at the temperature of 30.degree. C. for 180 sec.
Example 2
[0067] The composition for surface treatment is prepared with
aqueous solution of hexafluorotitanic acid (IV) and hydrofluoric
acid. The molarity ratio of Ti to HF in the composition is 8.0 and
Ti concentration is 40 mmol/L. Then Ba(NO.sub.3).sub.2 reagent,
Al(OH).sub.3 reagent, HBrO.sub.3 reagent and HNO.sub.3 are added,
and the composition for surface treatment is prepared
[0068] The prepared composition is diluted by water and the
treating solution for surface treatment has Ti concentration of 20
mmol/L, Ba concentration of 500 ppm, Al concentration of 20 ppm,
HNO.sub.3 concentration of 3000 ppm and HBrO.sub.3 concentration of
500 ppm.
[0069] After degreased, a test plate is rinsed by water and kept
into said treating solution adjusted to pH 4.0 using NaOH, at the
temperature of 30.degree. C. for 180 sec.
Example 3
[0070] The composition for surface treatment is prepared with
aqueous solution of hafnium oxide (IV) and hydrofluoric acid. The
molarity ratio of Hf to HF in the composition is 10.0 and Hf
concentration is 30 mmol/L. Then CaSO.sub.4 reagent,
Mg(NO.sub.3).sub.2 reagent and HNO.sub.3 are added, and the
composition for surface treatment is prepared.
[0071] The prepared composition is diluted by water and the
treating solution for surface treatment has Hf concentration of 10
m mol/L, Ca concentration of 500 ppm, Mg concentration of 250 ppm,
HNO.sub.2 concentration of 100 ppm and HNO.sub.3 concentration of
1500 ppm.
[0072] After degreased, a test plate is rinsed by water and kept
into said treating solution adjusted to pH 5.0 using ammonium
aqueous solution, at the temperature at 50.degree. C. for 60
sec.
Example 4
[0073] The composition for surface treatment is prepared by mixing
aqueous solution of hexafluorozirconic acid (IV) with aqueous
solution of hafnium sulfonate (IV) so as the weight ratio of Zr to
Hf to be Zr:Hf=2:1, and hydrofluoric acid. The total molarity ratio
of Zr and Hf to HF in the composition is 12.0 and total Zr and Hf
concentration is 10.0 mmol/L.
[0074] This composition is diluted by water, then
Sr(NO.sub.3).sub.2 reagent, Mg(NO.sub.3).sub.2 reagent,
Mn(NO.sub.3).sub.2 reagent, ZnCO.sub.3 reagent, HClO.sub.3 reagent,
H.sub.2WO.sub.4 reagent and HNO.sub.3 are added, and the treating
solution for surface treatment has total concentration of Zr and Hf
of 2 mmol/L, Sr concentration of 100 ppm, Mg concentration of 50
ppm, Mn concentration of 100 ppm, Zn concentration of 50 ppm,
HClO.sub.3 concentration of 150 ppm, H.sub.2WO.sub.4 concentration
of 50 ppm and HNO.sub.3 concentration of 8000 ppm.
[0075] After degreased, a test plate is rinsed by water and said
treating solution of the temperature is 45.degree. C. whose pH is
adjusted to 6.0 using KOH is sprayed to the test plate and the
surface treatment is carried out for 90 sec.
Example 5
[0076] The composition for surface treatment is prepared with
aqueous solution of zirconium nitrate (IV) and NH.sub.4F reagent.
The molarity ratio of Zr to HF in the composition is 6.0 and Zr
concentration is 10 mmol/L. Then CaSO.sub.4 reagent,
Cu(NO.sub.3).sub.2 reagent and HNO.sub.3 are added, and the
composition for surface treatment has Zr concentration of 0.2
mmol/L, Ca concentration of 10 ppm, Cu concentration of 1 ppm and
HNO.sub.3 concentration of 6000 ppm.
[0077] After degreased, a test plate is rinsed by water and kept
into said treating solution adjusted to pH 5.0 using ammonium
aqueous solution, maintaining the temperature at 70.degree. C. for
60 sec.
Example 6
[0078] The composition, for surface treatment is prepared with
aqueous solution of hexafluoro zirconic acid (IV) and
NH.sub.4HF.sub.2 reagent. The molarity ratio of Zr to HF is 7.0 and
Zr concentration is 5.0 mmol/L. The obtained composition is diluted
by water and Ca(NO.sub.3).sub.2 reagent, Mg(NO.sub.3).sub.2,
Zn(NO.sub.3).sub.2 reagent and HNO.sub.3 are added, and the
treating solution for surface treatment has Zr concentration of 1.0
mmol/L, Ca concentration of 1 ppm, Mg concentration of 2000 ppm, Zn
concentration of 1000 ppm and HNO.sub.3 concentration of 20000
ppm.
[0079] After degreased, a test plate is rinsed by water and soaked
into said treating solution for surface treatment adjusted to pH
4.0 using ammonium aqueous solution, maintaining the temperature at
45.degree. C. for 90 second.
Example 7
[0080] The composition for surface treatment is prepared with
aqueous solution of hexafluoro zirconic acid (IV) and hydrofluoric
acid. The molarity ratio of Zr to HF is 7.0 and Zr concentration is
50 mmol/L. The obtained composition is diluted by water and
Ca(SO.sub.3).sub.2 reagent, Sr(NO.sub.3).sub.2 reagent,
Cu(NO.sub.3).sub.2 reagent, H.sub.2MoO.sub.4 reagent,
35%-H.sub.2O.sub.2 aqueous solution and HNO.sub.3 are added, and
the treating solution for surface treatment has Zr concentration of
1.0 mmol/L, Ca concentration of 1 ppm, Mg concentration of 2000
ppm, Zn concentration of 30 mmol/L, Ca concentration of 150 ppm, Sr
concentration of 300 ppm, Cu concentration of 2 ppm,
H.sub.2MoO.sub.4 concentration of 1000 ppm, H.sub.2O.sub.2
concentration of 10 ppm, and HNO.sub.3 concentration of 30000
ppm.
[0081] After degreased, a test plate is rinsed by water and said
treating solution for surface treatment adjusted to pH 6.0 by NaOH,
maintaining the temperature at 50.degree. C. is sprayed and the
surface treatment is carried out for 60 sec.
Example 8
[0082] The composition for surface treatment is prepared with
aqueous solution of hexafluoro titanium (IV) and NaHF.sub.2
reagent. The molarity ratio of Ti to HF in the composition is 7.0
and Ti concentration is 20.0 mmol/L. Then Sr(NO.sub.3).sub.2
reagent, Zn(NO.sub.3).sub.2 reagent, H.sub.2MoO.sub.4 reagent,
HVO.sub.3 reagent and HNO.sub.3 are added, and the treating
solution for surface treatment has Ti concentration is 5 mmolL, Sr
concentration of 100 ppm, Zn concentration of 5000 ppm,
H.sub.2MoO.sub.4 concentration of 15 mmo/L, HVO3 concentration of
50 ppm and HNO.sub.3 concentration of 10000 ppm.
[0083] After degreased, a test plate is rinsed by water and kept
into said treating solution for surface treatment adjusted to pH
3.0 using ammonium aqueous solution, maintaining the temperature at
50.degree. C. and for 90 sec.
Comparative Example 1
[0084] The treating solution containing hafnium oxide and
hydrofluoric acid in which molarity ratio of Hf to HF is 20.0 and
HF concentration is 20 mml/L is prepared. After degreased, a test
plate is rinsed by water and kept into said treating solution for
surface treatment adjusted to pH 3.7 using ammonium aqueous
solution, maintaining the temperature at 40.degree. C. and the
surface treatment is carried out for 120 sec.
Comparative Example 2
[0085] The treating solution containing zirconium nitrate (IV) and
NH.sub.4HF.sub.2 reagent in which molarity ratio of Zr to HF is
10.0 and Zr concentration is 0.03 mml/L is prepared. After
degreased, a test plate is rinsed by water and kept into said
treating solution for surface treatment heated to 50.degree. C. to
which corresponding amount of Ba(NO.sub.3).sub.2 reagent to 10 ppm
of Ba, corresponding amount of Mn(NO.sub.3).sub.2 reagent to 1 ppm
of Mn and further adjusted to pH 5.0 using ammonium aqueous
solution and the surface treatment is carried out for 60
seconds.
Comparative Example 3
[0086] ALCHROM 713 (T.M.: product of NIHON PARKERIZING CO., LTD.),
a chromic chromate treating agent, is diluted to 3.6% by tap water,
then total acidity and free acidity of the prepared solution are
adjusted to the center value indicated in a brochure. After
degreased, a test plate is rinsed by water and is soaked in said
chromate treating solution at 35.degree. C. and kept for 60
seconds.
Comparative Example 4
[0087] PALCOAT 3756 (T.M.: product of NIHON PARKERIZING CO., LTD.),
a chromic chromate treating agent, is diluted to 2% by tap water,
then total acidity and free acidity of the prepared solution are
adjusted to the center value indicated in a brochure. After
degreased, a test plate is rinsed by water and is soaked in said
chromate treating solution at 40.degree. C. and kept for 60
seconds.
Comparative Example 5
[0088] The solution of PREPALENE ZTH (T.M.: product of NIHON
PARKERIZING CO., LTD.), zinc phosphate treatment, is prepared with
dilution to 0.14% by tap water. This solution is sprayed to said
test plate rinsed by tap water after degreasing at room temperature
for 30 sec. Then, the test plate is kept in a treating solution of
zinc phosphate at 42.degree. C. which is prepared by diluting
PALBOND L3080 (T.M.: product of NIHON PARKERIZING CO., LTD.) to
4.8% with tap water by adding 300 ppm of NaHF.sub.2 reagent as HF
to adjust the total acidity and the free acidity to the center
value indicated in a brochure. After this procedure the zinc
phosphate film if formed on the test plate.
[0089] The prepared test plates in above mentioned Examples and
Comparative Examples are tested and evaluated according to the
following test procedures, that is, an evaluation of surface
appearance, amount of treated film, corrosion resistance of treated
film and the performance on treated plate.
[0090] Surface Appearance of Treated Film
[0091] The appearance of surface treated plate obtained in Examples
and Comparative Examples are visually inspected. Results of
evaluation of surface treated film are summarized in Table 1.
1 TABLE 1 Appearance after surface treatment ADC Al Mg Example 1
U.W.C. U.W.C. U.W.C. Example 2 U.W.C. U.W.C. U.W.C. Example 3
U.W.C. U.W.C. U.W.C. Example 4 U.W.C. U.W.C. U.W.C. Example 5
U.W.C. U.W.C. U.W.C. Example 6 U.W.C. U.W.C. U.W.C. Example 7
U.W.C. U.W.C. U.W.C. Example 8 U.W.C. U.W.C. U.W.C. Comp. Example 1
White, uneven White, uneven White, uneven Comp. Example 2 Uneven
Uneven Uneven Comp. Example 3 G.C. G.C. G.C. Comp. Example 4 W.C.U.
W.C.U. White, uneven Comp. Example 5 White, uneven White, uneven
White, uneven In table 1, the meaning of each abbreviated codes are
indicated as follows; U.W.C.: uniform white color, G.C.: golden
color W.C.U.: white color uniform
[0092] Results of the test plates prepared in each Examples show
that the uniform films are formed. On the contrary, in cases of
Comparative Examples, an uniform film can not be formed on all test
plates except Comparative Example 3 of the chromate treatment.
[0093] Amount of Surface Treated Film Layer
[0094] The amount of surface treated film layer of surface treated
plates obtained in above mentioned Examples and Comparative
Examples 1 and 2 are evaluated with an X-ray fluorescence analyzer
(product of Rigaku Electric Industries: system 3270) by analyzing
quantitatively the elements contained in the treated film. The
results are summarized in Table 2.
2 TABLE 2 Deposit weight per unit of surface treated film layer
(total amount of Ti, Zr, Hf and Si: mg/m.sup.2) ADC Al Mg Example 1
33 27 25 Example 2 49 39 33 Example 3 40 34 31 Example 4 72 51 46
Example 5 31 23 18 Example 6 55 42 36 Example 7 52 45 41 Example 8
15 11 10 Comp. Example 1 9 6 5 Comp. Example 2 6 5 3 As shown in
Table 2, in all cases of Example, the aimed deposit weight per unit
of treated film can be obtained. While, in Comparative Examples 1
and 2, the deposit weight per unit is not attained to the aimed
value.
[0095] Evaluation of Coating Performance
[0096] (1) Preparation of Test Plate
[0097] For the purpose to evaluate the coating performance of
surface treated plates obtained in Examples and Comparative
Examples, coating is carried out by following procedure.
[0098] cathodic electrodeposition.fwdarw.coating rinsing by pure
water.fwdarw.baking.fwdarw.surfacer.fwdarw.baking.fwdarw.top
coating.fwdarw.baking
[0099] cathodic electrodeposition coating: epoxy type cathodic
electrodeposition coating (GT-10LF: product of KANSAI PAINT CO.,
LTD.), electric voltage is 200 V, thickness of film is 20 .mu.m,
baked at 175.degree. C. for 20 minutes.
[0100] surfacer: aminoalkyd coating (TP-65 white: product of KANSAI
PAINT CO., LTD.), spray coating, thickness of film is 35 .mu.m,
baked at 140.degree. C. for 20 minutes.
[0101] top coating: aminoalkyd coating (NEOAMILAC-6000 white:
product of KANSAI PAINT CO., LTD.), spray coating, thickness of
film is 35 m, baked at 140.degree. C. for 20 minutes.
[0102] (2) Evaluation of Coating Performance
[0103] The coating performance of surface coated plates of which
surface are coated by above mentioned process are evaluated.
Evaluation items, evaluation method and abbreviation marks are
shown below. Hereinafter, the coated film after electrodeposition
coating process is called as electrodeposition coated film and the
coated film after top coating is called as 3 coats coated film.
[0104] SST: salt spray test (electrodeposition coated film, and
corrosion resistance after surface treatment without coating.)
[0105] The electrodeposition coated plate having cross cut lines
with a sharpened knife is sprayed aqueous solution of 5%-NaCl for
840 hours (in accordance with JIS-Z-2371). After the test periods,
the maximum blistering width from both side of the cross cut line
is measured. While, corrosion resistance is measured by evaluating
white stain generated area (%) after 48 hrs. of salt water spray
without marking cross cut line by visual inspection.
[0106] SDT: hot salt water dipping test (electrodeposition coated
film)
[0107] An electrodeposition coated plate having cross cut lines are
marked by a sharpened knife is immersed into aqueous solution of
5%-NaCl at the temperature of 50.degree. C. for 240 hours. After
test period, rinsed by city water and dried in room temperature,
the cross cut part of electrodeposition coated film is peeled using
an adhesive tape, and the maximum peeled width from both side of
the cross cut part is measured.
[0108] 1st ADH: primary adhesiveness (3 coats coated film, before
immersion test)
[0109] 100 cross hatches of 2 mm width are marked using a sharpened
knife on a 3 coats coated film. The cross hatches are peeled using
an adhesive tape, and numbers of peeled hatches are counted.
[0110] 2nd ADH: water resistant secondary adhesiveness (3 coats
coated film, after immersion test)
[0111] A 3 coats coated film is immersed in pure water at
40.degree. C. for 240 hours. After immersion, 100 cross hatches of
2 mm width are marked using a sharpened knife on it. The cross
hatches part is peeled using an adhesive tape, and numbers of
peeled checker mark are counted.
[0112] The evaluation results of coating performance and corrosion
resistance of treated material without coating are summarized in
Table 3.
3 TABLE 3 Corrosion resistance of Coating performance of
electrodeposition uncoated metal SST: max. blistering SDT: max.
peeled SST: white width from width from both stain generated both
side (mm) side (mm) area (%) Al ADC Mg Al ADC Mg Al ADC Mg Example
1 0.3 1.1 2.5 0.5 1.6 3.2 5 5 10 Example 2 0.6 1.2 2.7 0.6 1.7 3.3
5 5 10 Example 3 0.4 1.2 2.6 0.7 1.5 3.0 5 5 10 Example 4 0.5 1.3
2.6 0.5 1.2 3.1 5 5 10 Example 5 0.5 1.5 2.5 0.5 1.3 3.1 5 5 10
Example 6 0.5 1.0 2.8 0.5 1.4 3.0 5 5 10 Example 7 0.3 1.2 2.6 0.5
1.5 3.3 5 5 10 Example 8 0.5 1.3 2.6 0.5 1.4 3.4 5 5 10 Comp. 0.6
2.1 3.5 1.0 2.0 5.0 30 30 40 Example 1 Comp. 1.5 2.8 4.0 2.2 2.3
5.2 40 50 50 Example 2 Comp. 0.5 1.2 2.6 0.3 1.5 3.1 5 5 10 Example
3 Comp. 0.6 2.0 3.2 0.8 2.1 6.8 40 60 70 Example 4 Comp. 0.5 2.2
10< 1.2 2.5 10< 50 70 80 Example 5
[0113] It is obvious from Table 3 that all test plates of Examples
good corrosive resistance. On the contrary, in Comparative Example
1, although the treating composition has the molarity ratio Ti to
HF of 20.0, neither the alkaline earth metal ion B of the component
(3) nor metal ion C of the component (4) causes the treated film
unsound. Consequently, the corrosion resistance of coated plates
are inferior to the test plates of Example treating. In Comparative
Example 2, the sufficient amount of film can not be obtained to
perform good corrosion resistance of uncoated test plate, because
the concentration of Zr, which is the main component of treated
film before coating, is small, 0.03 mmol/L.
[0114] Since the Comparative Example 3 is a chromate treating
agent, it indicates excellent resistance to corrosion of aluminum
and magnesium. Furthermore, since Comparative Example 4 is a
chromium free treating agent for aluminum alloy, the corrosion
resistance of aluminum is inferior to that of Comparative Example
3, relatively indicates good results. While unless the Examples are
chromium free treating, they show similar ability to chromate in
all items. Comparative Example 5 is a zinc phosphate treatment for
aluminum simultaneous treatment which is ordinary used as the base
coating for cathodic electrodeposition coating. Therefore, the
resistance to corrosion of aluminum is practically good. As shown
in Comparative Example 5, the corrosion resistance of Mg alloy, is
inferior to that of Examples, especially, regarding to corrosion
resistance of Mg alloy without coating, it can be said that not
attain the desired level in practical use.
[0115] The evaluation results of adhesiveness of 3 coats plates are
shown in Table 4. Examples 1-8 shows good adhesiveness to all test
plates.
4 TABLE 4 Coating adhesiveness of 3 coats coated film 1.sup.st ADH
2.sup.nd ADH Al ADC Mg Al ADC Mg Example 1 0 0 0 0 0 0 Example 2 0
0 0 0 0 0 Example 3 0 0 0 0 0 0 Example 4 0 0 0 0 0 0 Example 5 0 0
0 0 0 0 Example 6 0 0 0 0 0 0 Example 7 0 0 0 0 0 0 Example 8 0 0 0
0 0 0 Comp. Example 1 0 0 0 0 0 0 Comp. Example 2 0 0 0 5 5 8 Comp.
Example 3 0 0 0 0 0 0 Comp. Example 4 0 0 0 0 5 0 Comp. Example 5 0
0 0 0 0 0
[0116] According to the above mentioned results, it is obvious that
the treating solution for metal surface treatment, method for
surface treatment solution and surface of this invention treated
metal material with the present invention, can provide a metal
material with a film which has excellent corrosion resistance
either uncoated or coated of aluminum, aluminum alloy, magnesium or
magnesium alloy.
[0117] Further, in Comparative Example 5, sludge which is the
by-product at the zinc phosphate treatment generates in the
treatment both after treatment in the inventive process, the
generation of sludge is not observed at every Example.
INDUSTRIAL APPLICABILITY
[0118] The treating solution for metal surface treatment and the
method for surface treatment using present invention composition is
the epoch-making art which makes it possible to form the surface
treated film having in good corrosion resistance of metals without
coating, and corrosion resistance after coating on the surface of
aluminum, aluminum alloy, magnesium or magnesium alloy without
generating waste such as sludge and using treating solution not
containing harmful component to the environment such as hexavalent
chrome.
[0119] Since the metal material for surface treatment has an
excellent corrosion resistance to various environment and corrosion
resistance after coated, it can be used to various fields.
Furthermore, the present invention is enabled to shorten the
treatment procedure and to save the operating space, because the
zinc phosphate treating process usually used is not needed.
* * * * *